In the prior arts, although in the same backlight modules, different companies for manufacturing backlight modules may also have different assembly procedures. Because the different assembly procedures and differences in assembling techniques, different errors are then generated. The errors in assembling can easily influence the thermal expansion spaces for an optical film of the backlight module to further cause worse optical quality.
Therefore, if there is still a predetermined distance for positioning the lamp tube set and the light guide plate to satisfy the backlight module manufactured by different companies and the different assembly procedures, the required thermal expansion spaces are further provided for the optical film. The contribution would truly help the backlight module in the assembly procedures.
Referring to FIG. 1, a schematic diagram illustrates a conventional backlight module. In FIG. 1, the backlight module 1 includes a light guide plate 10, an optical film 11 and a lamp tube set 12. The light guide plate 10 can be inserted into the lamp tube set 12. The optical film 11 can be disposed on the light guide plate 10. In assembling the backlight module 1, in order to reduce influencing optical quality, a predetermined gap D1 is prepared for thermal expansion spaces generated by the optical film 11.
Referring to FIG. 2, another schematic diagram illustrates a conventional backlight module. In FIG. 2, the backlight module 2 as the same as shown in FIG. 1 includes the light guide plate 10, the optical film 11 and the lamp tube set 12. In assembling the backlight module 2, if a distance for the light guide plate 10 inserted into the lamp tube set 12 is too deep, the gap is reduced to become D2. The required thermal expansion spaces for the optical film 11 are insufficient, thereby changing the shape of the optical film 11. The optical image quality is getting worse. In addition, because the light guide plate 10 is so close to the lamp tubes (not shown) within the lamp tube set 12, the shape of the light guide plate 10 is changed due to heat energy generated by the lamp tubes. Furthermore, while performing an impact experiment for the lamp tubes, the lamp tubes may be hit by the light guide plate to cause broken.